JPH03213310A - Method and device for manufacture of preformed product - Google Patents

Abstract

PURPOSE: To effectively utilize energy and to maximaly put a material to practical use by preliminarily cutting a mat of a glass fiber reinforced material into a shape matched as a blank and adding a binder to the cut material and applying energy to activate the binder to rigidify the same. CONSTITUTION: A reinforcing material mat is preliminarily cut by a die cutter 62 so as to conincide with the developed shape of a preform. After the mat is cut, the binder and catalyst accelerator 70 from a binder resin source 68 are applied by ejection, rolling or calendering in a binder applying device 66. Next, the synthetic blank of this reinforcing agent and the binder is transferred to a mold 72 by a robot 74. The mold 72 is moved to a press 76 along a shuttle 78 and two half parts of the mold are pressed to duplicate the desired shape of the preform and energy is applied from a directional energy source 80. Next, by moving the mold 72 to a taking-out position along the shuttle 78, a robot 82 takes a cured preform 84 out of the mold 72.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a method for producing structurally reinforced preforms for resin transfer molding (RTM) and reaction injection molding (SRAM) processes for structural composites. and regarding equipment.

PRIOR ART AND PROBLEM TO BE SOLVED: In producing oriented fiber preforms, it has heretofore been possible to inject chopped fibers with a binder resin onto a molded part with air drawn through the molded part. It was practiced to position and hold the fibers using The molded article with the fibers and binder resin is then rotated into a hot air brenum chamber to dry and/or cure and fix the binder resin. In addition, a lot of storage space is required for the preforms to dry and harden. In making thermoformed preforms, it has heretofore been practiced by fiber manufacturers to use continuous strands of fiber that have been previously coated with a thermoplastic binder. The thermoformable mat is supplied in roll form, the cloak being rolled out in flat sheets of varying layer thickness and clamped at the edges into a holding frame. The frame network is then placed in an oven chamber containing radiant heaters that slowly heat the reinforcement mat and thermoplastic binder from both sides. Upon heating, the thermoplastic binder softens and, while softening, the frame network is rapidly transferred to a cold mold.

The mold is closed via a press that forces the reinforcing mat into the shape of the part. Upon cooling, the thermoplastic binder stiffens the thermoformable mat, thus holding it in its new shape. The above process is slow, requires a lot of space and requires a large amount of energy. When practicing the invention, the preform can remain in the manufacturing position and can only be ejected when the preform is cured. The present invention is even more energy efficient in that the binder resin is only heated using energy for curing. The reinforcement is not heated and neither is the compact. Therefore, a large area with a constantly operating oven is not required. The process is extremely fast since the curing range is seconds rather than hours.

The process requires very few volatile substances and is much safer for the environment in that nothing is evaporated as in systems that require heated ovens.

Conventional l for structural elements? In the application of the IM/SRIM method, the fiber layer thickness across the preform is increased to meet a range of strength requirements, thus using unnecessary material and increasing thickness and weight. I will let you do it. Additionally, neither the oriented fiber method nor the thermoformable mat method allows the designer to add ribs or sealing features to maximize design properties.

Thermoforming and directed fiber methods are slow, cumbersome and waste energy and materials.

It is known in the art to apply electromagnetic energy to influence elements in the process, such as the use of ultraviolet and microwave radiation.

As a specific example, like a conventional microwave oven,
The use of microwaves to generate heat is well known. Numerous applications for microwave heating include US patents for drying paper, textiles, veneers, food, medicine and the like. 3,597,567, U.S. Pat. No. 2.5
60.903 and US Pat. No. 3.277,580.

Such techniques can be used in implementing reinforcements. Also, airflow was incorporated into such systems to remove moisture created as steam during the drying process.

The purpose of the present invention is to perform resin transfer molding (RTM),
Resin injection molding (RIM) and structural reaction injection molding (SR
An object of the present invention is to provide new and improved methods and apparatus for using directed energy to produce structurally reinforced preforms for the IM) process.

Another object of the invention is to provide a method which is energy efficient, logical and basically simple and which allows maximum use of materials with as little possible waste as possible.

Still another object of the present invention is that in the design of preforms:
It gives the designer flexibility to include ribs, sealing profiles, cores, encapsulation of metal, foam, wood or other materials.

In accordance with the present invention, a method is designed for high-speed, high-volume production of stiffened composite molded parts that utilizes a wide variety of reinforcement materials to allow unlimited geometry and detailed assembly. Components such as structural foam, wood or metal, along with multiple fiber reinforcements, can be utilized to achieve any shape or structure.

The method of the present invention utilizes a specially developed bonding agent in conjunction with a directed energy system to utilize synthetic moldings and attach structural elements to the preform via energy stitch welding techniques. Its process capacity and binder system are
RTM and RIM resin systems, i.e. polyesters,
Applicable to and compatible with vinyl esters, urethanes, epoxies, phenolics and acrylic resins.

The method of the invention is designed to be completely automatic and to allow for the special distribution and placement of numerous types of reinforcement for the required structural properties of the preform, if necessary. . Therefore, complete freedom of design is inherent in the method and allows for the most desirable reinforcement types and/or structures, including closed structural profiles and various wall profiles that meet the design criteria. The process of stiffening and/or mounting the component structure can be varied to suit the molding machine cycle time, or feeding different or multiple preforms to more than one molding machine. can do.

The automation of the process is designed to make full use of statistical processing techniques to produce repeatable - consistent quality and structural integrity preforms. Applications of the method technology can be incorporated into a wide variety of product ranges such as marine, aircraft, aerospace, defense and sports, and consumer products.

As discussed in more detail below, a directed energy system as well as engineered polymer resin chemistry is used in conjunction with specially designed automated machinery for the production of structural carrier preforms. The preforms are RTM and S
It can be tailored to the special structural and dimensional requirements needed for RIM components.

The major problems with placing reinforcements during preforming and molding can be overcome by combining and stiffening various reinforcements to fit the desired complex shape.

Due to the features of the present invention, the use of other reinforcements can be integrated with the preform structure by adding stiffeners or ribs, and reinforcement for the structure as well as class A
Encapsulation of the core material with the insert can be achieved if application of the core material is required.

In practicing the present invention, mats of glass fiber reinforcement are precut into matching shapes as blanks, a binder is added, and each blank is then cut using a specially engineered method that directs energy into the preform binder. Processed and transferred into a mold set that replicates the shape of the part. Energy is applied for a few seconds to activate the binder and then stiffen the preform. When the activation energy is turned off, the mold set is opened and the preform is transferred to the molding station or to any energy stitch welding station.

The preformable reinforcement mat is cut into a predetermined pattern that allows it to match the contours of the mold. Impregnate both sides of the reinforcement with binder resin. Single or multi-layer reinforcement mats are sandwiched together to provide a carrier preform charge. Carrier preform refers to a preform in the process of being used as a subassembly or having reinforcements that are subsequently attached by energy stitch welding to create the final assembly. For Sean Lawton (C, A,
This is a term coined by the Lawton Company. Energy stitch welding is used to describe the process of placing and attaching a structure to a basic preform.

This is a term coined by the Lawton Company. The binder resin is used as catalyst-promoted (microwave system) or supplied for the UV system and is metered into the application system. When adding the binder, the binder resin can be jetted and rolled or calendered as a film. After adding the binder, the reinforcement mat is placed in the balanced half of the mold (
(male or female).

The mold is rapidly transported into a forming press and connected to a directed energy source. The forming press closes to form the reinforcement mat into the desired shape. While closed, ultraviolet energy is applied to the mold, thus rapidly curing the catalytic binder resin. When the binder resin cures, it polymerizes into a rigid mass that allows the preform to retain the shape of the mold. When the binder generates heat for reaction or the energy is turned off in an exothermic system, the glass reinforcement can act as a heat sink and cool the preform. Heating of the glass is minimal. This is because it does not absorb energy from the input power, but only from the heat released from the binder reaction. Heating of the mold surface is therefore also minimal.

The reinforcement mat no longer needs to be heated, it is stretched to match the shape of the carrier preform and allowed to cool. Once again, when required and to be made rigid, profiles can be added in place by the previously mentioned chemical stitch welding technique called energy stitch welding.

Although conventional preforming methods are currently being improved with automation, they generally remain operator dependent. The present invention is designed for industrial manufacturing methods that provide complete products with a high level of automation.

With the use of automation/robots, the glass distribution becomes very uniform and repeatably consistent, making all aspects of the process statistically controllable.

After the stiffening cycle, the forming press is opened and the mold is quickly transported out where the carrier preform is mechanically removed and transported to another processing location for insert application or molding. .

When applying conventional RTM/SRIM molding techniques to structural elements, the fiber layer thickness is adjusted to resist strength requirements. Energy stitch welding allows reinforcement to be selectively and specifically added to high stress ranges without increasing overall thickness and weight. Therefore, the method of the present invention is useful for two types of stitch welding techniques: microwave and ultraviolet. The application of inserts, closure profiles and/or cores to carrier preforms can be processed using energy stitch welding techniques. Pre-cut sections of reinforcement can be tack-welded in place using a secondary microwave or ultraviolet energy application device. When using microwave energy, the carrier preform with added reinforcement and binder is placed into a forming press or into a secondary clamping device that holds the material in place while the energy is applied. can be quickly transported to Similarly, in the UV stitch welding method, the reinforcement is pressed into place, a special UV-sensitive binder resin is applied at specific point locations, and then UV energy is applied to cure the binder resin.

The finished preform can be transferred to a holding area or directly to a molding operation. Since the stiffening of the preform is faster than the molding cycle, different molds can be installed during the stiffening process, thus making it possible to create a large number of preform appendages for feeding other molding stations. I can do it.

Material factors are critical to effectively accomplishing the stiffening process. During microwave applications, synthetic materials with very low electrical losses are required for the mold surface. The microwave energy cannot affect the material used in the mold and the mold material cannot absorb the energy required to stiffen the preform. The mold material also requires good thermal stability with respect to the heat generated by the preform binder. Although the heat generated is minimal, repeated cycling may cause significant heat generation. On the other hand, the materials used as stiffening binders have high electrical loss properties in response to microwave energy and are therefore very useful in this method.

To facilitate directed energy preforming systems,
A suitable binder system is required. Typical standard binders used in conventional preforming are usually thermosetting polyesters or various thermoplastic polymers. For directed energy processes, the requirements are even more stringent. If a thermoplastic binder is used in the carrier preform, the thermoplastic binder will soften during the addition of the fiber inserts and when the directional strength is added again to further strengthen the various areas of the part to be molded. and leave. Therefore, in some cases, a thermoplastic binder may be satisfactory for the accessory, but not for the main carrier preform. For this purpose, thermosetting polymers are required. Additional requirements are also necessary. The binder must be compatible with the various matrix resins used with the preform. This includes polyesters, vinyl esters, polyurethanes,
Includes polyisocyanates, polyureas, JPN resins, and polyester/urethane hybrids (and possibly epoxies). It would be particularly useful if chemistry could be used for all of the potential matrix resins. In addition to the above requirements, the binding agent for this method must be highly active in response to directed energy. Here, the binder resin is specially chemically structured so that it is itself highly active in response to applied energy. Importantly, when energy is applied, the binder is activated and hardens within seconds. Since heat can be part of the curing process, the heat must be generated quickly when the energy is introduced, but the heating must be stopped momentarily when the energy is finished. If a binder system is selected that generates heat for reaction or is exothermic, the reinforcement acts as a heat sink and is largely prevented from heating the preform itself. Heating the mantle is not a prerequisite for this method, so the reinforcement to which the binder has been added is vacuumed into shape before activating the binder system, as in the case of thermoforming formats. be able to. Further application of directed energy after curing is complete does not further activate the binder, or at least does not degrade or release the bonding properties. After stiffening, the binder in the cured state becomes sufficiently transparent to the applied energy to prevent degradation or loss of its stiffening properties. This is particularly important for attaching inserts. Most thermosetting polymeric binders that are highly active to directed energy tend to be highly active during the initial stages of curing, but with decreasing activity as curing continues. Therefore, it is difficult to obtain complete curing.

This is because the polymer stops absorbing energy.

Air suppression also affects the completion of curing.

Because the cure is incomplete, bonding sites are available for the matrix resin and therefore physical properties will be enhanced when molding is complete. Other thermoset polymeric binders are highly active throughout the curing process, and when volatile additives such as monomers are used, excessive heating and degradation of the binding capacity of the binder occurs.

In the case of microwave directed energy systems, the reaction temperature of the binder resin is designed for low temperatures, but well above the environment to allow adequate processing shelf life when enhanced. Localized and directed heating from an energy source can achieve temperatures in excess of 300° F., which are sufficient to complete curing. Special binders developed for use in practicing the invention with microwave technology are available from Freeman Chemical Corporation (Freema).
n Chemical Corp, ) Stypol (S
typol) XP44-A Formerly known as 2-51B. This is a diluted version of Freeman 4
4-7010 binder. This binder has the necessary curing properties under applied energy, a suitable chemistry that is compatible with all the necessary matrix resins, and is suitable for most organic reinforcing fibers as well as for glass fibers. It also has good adhesion, excellent bonding properties and production of rigid preforms. The binder is also compatible with any additional binders used in attaching or adding the fiber component insert.

Glass fibers in the form of cloaks for carrier preforming are ideal for load-bearing parts. Continuous strand preformable mats lend themselves to easily conforming to part shapes during the forming process and can be advantageously used to produce preforms.

Multiple layers of reinforcing material 77) can be simultaneously molded into a desired shape.

Other types of reinforcement can be stiffened, ribbed and encapsulated for attached components using energy stitch welding techniques. These types of reinforcements,
Fibrous, metallic and/or lightweight structural foams and low-density cores are added to the carrier preform at the beginning of the charging and shaping process when placement of insert material is necessary for the preform construction. It can be added as a component or as a secondary operation.

When matte materials are used in specific locations with unidirectional fabrics or other reinforcements, an optimal reinforcement structure with high fiber content can be achieved, as well as for easy handling and penetration of the resin system during molding operations. A rigid shape can be maintained.

By placing the reinforcement in specific locations, fiber orientation can be achieved where necessary to obtain the required strength of the molded product.

In actual testing, two directed energy power sources were used both separately and in conjunction with each other.

The directed energy power source used in the actual test was
It is an O-6'kw-' microwave generator operating at 2450 MHz. Power level requirements depend on the dimensions of the forming tool relative to the mass of the material charge. An initial bower level calibration is required to optimize the stiffening cycle time.

The energy level reflected from the power output is controlled. For larger molding tools requiring higher power, additional generators can be added. Power ramping to reduce power can be used to compensate for the binder curing process. because,
This is because during the reaction the binder becomes somewhat transparent to the energy field and therefore does not require sufficient output power. Also,
Power ramping extends generator life and prevents power surges.

Directed energy for energy stitch welds and reinforcement inserts for the application of localized microwave energy or for directing energy to specific locations on the preform to cause polymerization of the stitch weld binder resin consists of ultraviolet energy levels.

For UV curing systems, a similar mold structure is used, except that the UV radiation source is included within the body of the preform mold after the mold surface.

The mold surface can be constructed of a metal screen, clear acrylic or other rigid material that allows ultraviolet radiation to pass through and into the preform. Materials such as clear acrylic are desirable because they can be inexpensively thermoformed into complex shapes and are easily replaced when wear is apparent.

A specially designed synthetic material is used to form the shape of the preform. For more complex shapes, a combination of preform molds can be used simultaneously with the same energy source or with several independently formed features (subassemblies) and later combined with the entire preform operation. Can be joined by energy stitch welding. The tool is designed not only to shape the preform, but also to specifically direct the energy into the binder-containing reinforcement. The key to this design relies on positioning the preform portions in areas of highest curing energy intensity and appropriate tooling configuration to evenly distribute the energy waves. To effectively achieve directed energy uniformity in microwave technology, three-dimensional matched waveguides are placed in a direct design to produce multiaxial wave formation. Since the waveguide consists of a channel with a particular cross-sectional dimension in which the maximum energy is centered, the waveguide is divided and each half is placed on the surface of a corresponding half of the mold. To achieve wave tuning without moving the waveguide or material, the contours of the mold design create a snake-like pattern. It is also important to maintain appropriate cross-sectional dimensions within the waveguide ends. Bend manufacturing must be carefully considered to achieve optimal performance. Each hand portion of the waveguide has three sides made of metallic material with a fourth side facing the preform material, consisting of a material that is transparent to microwaves and acts as a mold surface. Consisting of The spacing between each corresponding half of the mold cavity or waveguide section must be designed to prevent stray energy losses and ensure proper cross-sectional dimensions of the waveguide. Towards the center of the mold surface area, the spacing can be increased to allow cross-tuning of the waves.

〔Example〕

Hereinafter, the present invention will be explained in detail with reference to embodiments shown in the drawings.

Referring to FIG. 1, the basic tool is shown generally at 10 as consisting of a segmented serpentine waveguide 12 having an upper portion 14 and a lower portion 16, which portions are essentially They are mirror images of each other, separated by a gap 18 and provided with a microwave input fitting 20. waveguide 1
4 consists of a top wall 24 and a side wall 26 forming a snake-like structure. A synthetic material in the form of a web 22 is located in gap I8 for applying microwave energy.

A structure of the type used to test the present invention is shown generally at 28 as consisting of a segmented microwave waveguide 30, with an upper portion consisting of side walls 32 and a top wall 34. has. The sidewalls 32 are contoured to match the contours of the molds indicated at 36 and 38;
It has an inner surface 40 and an inner surface 42 that match the shape of the preform to be molded. The materials carrying surfaces 40 and 42 and the support material between those surfaces and the waveguide are transparent to microwave energy. The waveguides are provided in sections and have couplings as indicated at 44 to each other and for the input of microwave energy. A composite material of reinforcement and binder resin is shown at 46 between surfaces 40 and 42. Once the composite material 46 is loaded into the mold section of the tool, microwave energy is applied to activate the binder resin for curing.

Turning to the flowchart of FIG. 3, a typical method for carrying out the present invention is shown at 48 and includes a reinforcement material (glass fiber mat) and an uncured stiffening material (bonded 50 of stacked layers of binder resin) formed by adding a binder resin to the reinforcement. Alternatively, method 48 may alternatively include injecting 52 an uncured stiffening material onto the reinforcement mat. The blank is then cut at 54 to match the flattened shape of the preform. At 56, the blank is pressed into a preform shape in a mold and microwave energy is applied at 58 to cause curing of the binder.

At 60, the binder is cured and hardened, and the stiffened preform can be removed from the mold.

FIG. 4 shows a similar method using a robot to handle materials between processing stations.

In FIG. 4, the first step is to pre-cut the reinforcement mat to match the developed shape of the preform, as shown by die cutter 62. This is an alternative step to the initial part of the method shown in FIG. After the mat is cut at 62, a binder is added at 64 in a binder application device 66, which includes a source of binder resin 68 and a catalyst promoter 70. As previously discussed, the binder is applied by spraying, rolling or calendering in the binder applicator 66. The reinforcement and binder composite blank is then transferred from the binder applicator to mold 7.
2 by the robot 74. The mold 72 may be of the type shown in FIG. 2 such that the composite blank is located in the male portion of the mold as shown at 42.46 in FIG. Returning to FIG. 4, mold 72 is then moved along shuttle 78 to press 76 where the two halves of the mold are pressed to replicate the desired shape of the preform and energy is applied to the microwave. The energy is applied from a directed energy source 80, such as energy.

The robot 82 then removes the cured preform 84 from the mold 72 by moving the mold 72 along the shuttle 78 to the removal position. Here, the preform is
This results in a carrier preform in that the reinforcement must be applied in the form of a reinforcing structure. Then robot 8
2 stack the preform for short-term storage or transfer it directly to the energy stitch welding process.

When the element has to be stitch welded to the carrier preform, the reinforcement is precut as before at 86 and the robot 88 forms it so that the precut material assumes the reinforcement shape 92. Position above -90. Robot 94 then retrieves preform 84, now a carrier preform, and places the carrier preform onto molded element 92. There is a point (not shown) where carrier preform 84 and molded element 92 engage in intimate contact. When the energy stitch welding process utilizes microwave energy, element 92 includes a binder resin. When the energy stitch welding process relies on ultraviolet energy, ultraviolet sensitive binder resin is added at specific point locations where elements 84 and 92 are intimately engaged.

Ultraviolet energy is then applied for curing and bonding. In either case, a directed energy source 96 is then used to cure the bonding agent and bond the two elements together to form a reinforced structure 98. Structure 98 is then transferred to a molding process for forming the final structure.

As can be seen from the above, attachments for a molded final product by bonding the appendage to the carrier preform to increase the structural strength of the molded final product or by energy stitch welding of the elements to the preform. You can add devices. One element that should be attached to another element,
It is not necessary to create by the same energy-directing process or by struggling energy-directing processes. To attach one element to another, a microwave or ultraviolet sensitive binder resin may be added and a corresponding energy applied to cure the binder resin. Therefore,
This flexibility is an advantage of the energy stitch welding process in that preforms produced by microwave technology have reinforcement elements by energy stitch welding using ultraviolet light technology and vice versa. Also, elements such as wood, steel, carbon black, and the like can be attached to the preform using either technique in combination with a suitable binder resin.

In FIG. 5, the tool is shown at 100 as consisting of a pair of separable mold sections including a molding member 102 having a complementary molding member 104. As shown in FIG.

The molding members 102, 104 are made of microwave transparent material and form the inner surface of the mold cavity. The remainder of the mold is formed thereon and includes an outer layer 106, 108 and a plurality of waveguide sections 110 connected to the serpentine waveguide via a plurality of radial sections 112.

When the two parts are brought together, a complete waveguide is formed, and there is a space between layers 102 and 104 that defines the mold cavity. As shown at 114 and 116, the mold may include a support material such as wood, foam or resin.

The use of ultraviolet light in making preforms was mentioned above. This technique places an ultraviolet light source in a forming tool to direct ultraviolet radiation toward a fiber-reinforced preform to form a stiffened structure.

A glass fiber reinforcement containing a stiffening binder resin is placed between the two counterbalanced halves of the tool.

When UV radiation is applied, the binder resin undergoes molecular polymerization that forms a rigid product capable of holding the glass fiber material into the conforming shape of the tool.

Similar to microwave technology, a binder resin that is molecularly sensitive to ultraviolet radiation is added to the glass fiber reinforcement. The reinforcement is then placed in a mold that is made to match the shape of the final part. When joining the two halves of the mold, the fibrous material conforms to the shape of the mold. The surface of the corresponding half of the mold in contact with the fibrous material is
Made of materials that transmit ultraviolet radiation.

This material can be a solid transparent acrylic type thermoplastic or a metal wire mesh screen. Therefore, a violet momme light source is placed within the forming tool structure,
Radiation is directed through the mold surface and into the fibrous material. For simple molding tools, the light source is placed into an open chamber below the mold surface. For more complex preform shape requirements where structural support to the mold surface is required,
An ultraviolet light source is placed in the multichamber section and simultaneously energized to perform the stiffening operation.

It has been found that binder resins consisting of the following can be used in ultraviolet technology. These are available from Freeman Chemical and 80497 (Slow System), 747-
10 (media system) and 19-4837 (rapid system). The application is similar to that of microwave technology.

Referring to FIG. 6, a tool for an ultraviolet process is shown comprising an upper mold part 120 and a lower mold part 122.
18. The mold surfaces are 124 and +
26. A chamber 128 is formed by the mold part 126 of the lower mold part 122 and has a plurality of ultraviolet light sources 130-140 mounted therein.

When the mold is closed, as shown in Figure 7, the synthetic material
It is made to conform to the shape defined by mold surfaces 124, 126, and the shape is made rigid by applying ultraviolet energy from #130-140.

Referring to FIGS. 8 and 9, another tool is shown at 144 as consisting of an upper mold part 146 and a lower mold part 148. As you can see, the upper mold part is
Side wall 15o, side wall 152, top wall 154, and mold wall 16
and an inner wall completed by 0. Lower tool part 14
8 has an inner wall completed by a lower wall 170 and an Oyohi-type wall 172.

At the top, walls define a chamber 164 on either side of the mold wall 160. Ultraviolet light sources 166 and 168 are mounted within chamber 164. In the lowest part 148, the bottom wall 1
70 and a mold wall 172 define a chamber 174. A UV light source 176 is attached to chamber 174.

When the mold is closed, the synthetic material is exposed to the ultraviolet light source 166, as shown closed along the dividing line 178 in FIG.
, 168 and 176 can receive ultraviolet radiation.

Although the invention has been described with reference to specific illustrative embodiments thereof, it will be apparent to those skilled in the art that numerous changes and modifications may be made thereto without departing from the spirit and scope of the invention. It is therefore intended to cover within the scope of the patent warranted herein all such changes and modifications as may reasonably and properly come within the scope of the invention's contribution to the art.

〔Effect of the invention〕

The present invention provides resin transfer molding (RTM), resin injection molding (RIM) and structural reaction injection molding (SRIM).
) A new and improved method and apparatus are provided for using directed energy to produce structurally reinforced preforms for use in a method. The invention is also energy efficient, logical, fundamentally simple and allows maximum use of materials with as little possible waste as possible. Additionally, the present invention allows flexibility to the designer in the design of the preform, including the inclusion of ribs, sealing profiles, cores, metal, foam, wood or other materials.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a segmented serpentine waveguide sandwiching the synthetic material to be cured, and FIG. 2 is a perspective view of a tool constructed in accordance with the present invention, in which each part is a segmented serpentine waveguide. Consists of one piece separable mold carrying each part of the. FIG. 3 is a block diagram flowchart showing the basic method of the invention, FIG. 4 is a schematic diagram of an automated process for implementing the invention, and FIG. 5 is a diagram that can be used in implementing the invention. Figure 6 is a schematic perspective view of a tool constructed in accordance with the present invention, in which the binder resin is stiffened by irradiating the blank with ultraviolet energy from a source mounted within one of the parts; It consists of a separable mold in two parts that can be operated in the same way. FIG. 7 is an end view of the tool of FIG. 6, and FIG. 8 is a schematic perspective view of another embodiment of a tool constructed in accordance with the present invention, in which ultraviolet energy is applied by a source attached to each of the mold parts. It consists of a two-part separable mold that reacts to stiffen the binder resin. FIG. 9 is an end view of FIG. 8. 12, 14.30.110... waveguide, 40.42;
124.126...Mold surface, 46...Synthetic material of binder resin and reinforcing material, 72; 102.104;120
．． 122; 146.148...Mold, 76...Press, 78...Shuttle, 80...Directed energy source, 84...Preform

Claims (1)

[Claims] (1) Cutting a blank of a predetermined shape from a mat of reinforcement, adding a binder resin to the blank, shaping the blank into the shape of a preform, and applying electromagnetic energy to the shape. A method for producing rigid preforms comprising the step of stiffening a binder resin in addition to a blank that has been prepared. (2) Adding a binder resin to the glass fiber reinforcement to form a composite blank, pressing the composite blank into a predetermined shape, and adding ultraviolet energy to the pressed blank to polymerize and press the binder resin. A method for producing a rigid preform, comprising the steps of: stiffening a blank into a rigid preform. (3) A method of producing a stiffened preform from a composite of a flexible blank of reinforcement and an uncured stiffening material, in which the blank is pressed into the shape of the preform in a mold and A method consisting of applying electromagnetic energy to the blank during a period of time to harden the stiffening material. (4) A method for producing a preform from a flexible reinforcement and an uncured stiffening material, in which a layer of uncured stiffening material is added to and impregnated with a layer of the flexible reinforcement. forming and cutting a blank from the impregnated layered structure, pressing the blank in a mold having a mold cavity of the dimensions and shape of the preform;
and applying ultraviolet energy to the pressed blank while in the mold to cure and stiffen the stiffening material. (5) Cut the blank from the mat of reinforcement, add binder resin to the blank, place the blank between the two parts of the mold, quickly transport the mold to the press, and put the two mold parts together. a rigid preform consisting of pressing with electromagnetic energy to the blank to stiffen the binder resin, rapid transport of the mold from the press, and removal of the rigid preform from the mold. How to manufacture. (6) comprising a mold including a cavity having a predetermined shape;
The mold has first and second separable mold parts, each mold part defining a portion of the mold cavity, and a separable waveguide having the first and second parts; the first waveguide component is attached to the first mold component, and the second waveguide component is attached to the second mold component;
A molding tool for producing a preform, also comprising a source of microwave energy coupled to said waveguide. (7) In a forming tool for producing a preform having a predetermined three-dimensional shape from a synthetic material comprising a reinforcing material and a stiffening material, first and second separable parts for receiving the synthetic material therebetween; a microwave guide comprising mold parts having cooperating separable mold surfaces which form said predetermined three-dimensional shape when joined, and having first and second parts; a waveguide, the first part carried by the first mold part and the second part carried by the second mold part, the waveguide causing hardening of the stiffening material; A molding tool that can be biased in the same way. (8) a cutting means for cutting the glass reinforcing mat into blanks of a predetermined shape, and a binder application device for adding a binder resin to the blank to form a composite blank of reinforcement and binder resin material; a mold having first and second separable mold parts defining a mold cavity together for receiving and pressing a reinforcement carrying a binder resin; and a first and second separable mold part. a microwave waveguide having a wave tube section, the first section attached to the first mold part and the second section attached to the second mold part, and a microwave input section; and charging means for placing a composite blank of reinforcement and binder resin into said mold cavity, and for pressing said mold parts together such that the blank replicates the shape of the preform. a press; a shuttle for transporting the mold into and out of the press; and a shuttle for connecting to the microwave input for energizing the microwave waveguide and causing curing and stiffening of the binder resin. Apparatus for producing a rigid preform, comprising: a microwave generator; and ejection means for ejecting the rigid preform from the mold. (9) applying a point location of electromagnetic energy sensing binder resin to the reinforcement element, moving the reinforcement element into intimate contact with the carrier preform at the point location, and applying electromagnetic energy to the point location of the reinforcement element; A method of attaching reinforcement elements to a preform carrier comprising the additional steps of stiffening the binder resin and bonding the reinforcement element to the preform carrier. (10) applying a point location of microwave sensitive binder resin to the reinforcement element, moving the reinforcement element into intimate contact with the carrier preform at the point location, and applying microwave energy to the reinforcement element point location; A method of attaching a reinforcement element to a preform carrier comprising the steps of: stiffening the binder resin in addition to positioning and bonding the reinforcement element to the preform carrier. (11) applying a spot location of UV-sensitive binder resin to the reinforcement element, moving the reinforcement element into intimate contact with the carrier preform at the spot location, and applying UV energy to the spot location of the reinforcement element; A method of attaching reinforcement elements to a preform carrier comprising the additional steps of stiffening the binder resin and bonding the reinforcement element to the preform carrier.